Due to the long time in vehicular cabins, people have high exposure to the airborne volatile organic compounds (VOCS), which will lead to negative effects on human health. In order to analyze the influencing factors of in-car VOCS pollution concentrations, 38 taxis were investigated on the static and closed conditions. The interior air of taxis was collected through activated Tenax adsorption tubes, and the air samples were analyzed with thermally desorbed gas chromatograph. The average concentrations of in-car benzene, toluene, ethylbenzene, xylenes, styrene, butyl acetate, undecane, and total VOCS (TVOC) were 82.7, 212.3, 74.7, 182.3, 24.7, 33.5, 61.3, and 1,441.7 μg/m(3), respectively. Furthermore, the VOCS and TVOC concentrations increase with the rise of in-car temperature and relative humidity, and decrease with the increase of car age and total mileage. In addition, the VOCS and TVOC concentrations are higher in vehicles with small cabins than in ones with big cabins, and change with different sampling sites and various vehicular grades. Finally, according to the multiple linear regression analysis and hierarchical cluster analysis, car age is the most important factor influencing airborne VOCS and TVOC pollution concentrations in vehicular cabins, followed by interior temperature and total mileage.

Interior air environment and health problems of vehicles have attracted increasing attention, and benzene homologues (BHs) including benzene, toluene, ethylbenzene, xylenes, and styrene are primary hazardous gases in vehicular cabins. The BHs impact on the health of passengers and drivers in 38 taxis is assessed, and health risk equations of in-car BHs to different drivers and passengers are induced. The health risk of in-car BHs for male drivers is the highest among all different receptors and is 1.04, 6.67, and 6.94 times more than ones for female drivers, male passengers, and female passengers, respectively. In-car BHs could not lead to the non-cancer health risk to all passengers and drivers as for the maximal value of non-cancer indices is 0.41 and is less than the unacceptable value (1.00) of non-cancer health risk from USEPA. However, in-car BHs lead to cancer health risk to drivers as for the average value of cancer indices is 1.21E-04 which is 1.21 times more than the unacceptable value (1.00E-04) of cancer health risk from USEPA. Finally, for in-car airborne benzene concentration (X, μg/m(3)) to male drivers, female drivers, male passengers, and female passengers, the cancer health risk equations are Y = 1.48E-06X, Y = 1.42E-06X, Y = 2.22E-07X, and Y = 2.13E-07X, respectively, and the non-cancer health risk equations are Y = 1.70E-03X, Y = 1.63E-03X, Y = 2.55E-04X, and Y = 2.45E-04X, respectively.

The microwave drying performance of lignite thin layer in a bench-scale setup was highlighted in terms of three additives with 10% dosage. The dielectric loss for dried lignite, raw lignite, lignite/coal fly ash, lignite/Na 2 SO 4 and lignite/Na 2 CO 3 at 2450 MHz were 0.06, 0.13, 0.14, 0.15 and 0.18. In comparison with raw lignite, the average temperature rising of the thin layer at 385 W for lignite blending with sodium carbonate, sodium sulfate and coal fly ash was about 10, 7 and 2 °C. The apparent activation energies of both falling rate periods for lignite blending with three additives were less than that of raw lignite. Sodium carbonate among three additives could be preferable one, followed by sodium sulfate and coal fly ash. The energy efficiency increased with the addition of sodium carbonate, sodium sulfate and coal fly ash. The required electricity energy for lignite/Na 2 CO 3 blend at 385 W was reduced by about one half in compared with the raw lignite.

No abstract

No abstract

In this study, groups of batch experiments were designed to identify the characteristics of alum sludge for arsenic (As) adsorption. Air-dried alum sludge (moisture content 13.9%) collected from a water treatment works in Xi'an, China, was subjected to artificial As-rich wastewater adsorption tests using As 2 O 3 as a model As source. Adsorption behaviours were investigated and the results have shown that the Langmuir adsorption isotherm well fits the experimental data (R 2 = 0.94957-0.99365). The maximum adsorption capacities range from 0.61 to 0.96 mg-As/g when the pH of the As solution was varied from 9.0 to 4.0. The prospects in China for the outcome of this study are discussed. This promising low-cost technique can eradicate As contamination in China.

No abstract

No abstract